Minimum viable TimeDetectorService

This is a do-nothing DeviceContextualizerService that can be
populated in following commits. A temporary method has been
added so the service has one method.

Unit tests can be run with:

atest FrameworksServicesTests:TimeDetectorServiceTest

Test: build / boot
Test: See above
Change-Id: I9e4eac70b944441f34491315cd1ce7fa2b9ae150